Patent GB-572694-A (GB)
Title: Improvements in and relating to systems for transmitting torques from a driving mechanism to a driven mechanism
IPC: F16H3/44
Filed: 1939-12-11
Abstract: 572,694. Variable-speed gearing. ROBIN, L., and ROGGEN, M. VAN. Dec. 11, 1939, No. 31966. Convention date, Dec. 13, 1938. [Class 80 (ii)] In gearing comprising a three-element epicylic train having one element connected to a driven shaft, and the other elements connected to two driving-shafts, one or both of which are provided with torque or speed varying-means, a freewheel device transmits to the framework the reaction on the element associated with one of the driving-shafts when the latter is disconnected. The motor M, Fig. 1, drives, through change-speed gearing H<1>, H<2>, shafts 1<1>, 1<2>, the shaft 1<1> being provided with a sun-wheel 3 co-operating with planet-wheels 4 which are carried by the driven shaft 2 and co-operate with an annulus 5 which is coupled to the shaft 1<2> by a sprocket-chain 6. Initially, the annulus is stationary, and the shaft 2 is driven with a low gear-ratio by the shaft 1<1>. To prevent reaction-torque on the shaft 1<2>, the annulus is provided with a ratchet-wheel 13 which cooperates with a pawl 14 mounted on the framework 15. When the shaft 1<2> is thrown in, the annulus is driven, and the shaft 2 is driven with a high gear-ratio. The shaft 1<2> may be thrown in or out under control of the reaction-torque. For instance, the pawl 14 may be supported by a piston 18 which transmits pressure to a diaphragm 20 for locking or operating the control-lever 21<2> of the gear-box H<2>. To prevent transmission of excessive reaction from the driven shaft, the shafts 1<1>, 1<2> are provided with freewheel devices 17 co-operating with the framework. In a modification of the gearing shown in Fig. 1, the annulus and the planetcarrier are geared to the driven shaft 2 and the shaft 1<2> respectively. In another modification, the shaft corresponding to the shaft 2 is coupled by a sprocket-chain to the annulus of an epicyclic train associated with the driven shaft. The change-speed gearing H<1>, H<2> may be of the continuously-variable type comprising a disc and roller. Alternatively, the change-speed gearing described in Specifications 490,359 and 491,645 may be employed. The shafts 1<1>, 12 may be operated by separate electromotors, preferably arranged in tandem, the shaft 1<1> and the annulus 5 being provided with freewheel devices consisting of ratchet-wheels co-operating with pawls. A relay-controlled contact is provided for switching in the second motor when the current through the first motor drops below a certain value. In the construction shown in Fig. 15 the rotor R and stator S of a single electromotor drive a shaft 1<1> provided with a sun-wheel 3, and a sleeve 1<2> provided with an annulus 5 respectively, the sun-wheel and annulus co-operating with planet-wheels 4 carried by the driven shaft 2. The shaft 1<1> and the annulus are provided with ratchet-wheels 16, 13 which co-operate with pawls 17, 14 on the housing M. The rotor drives the shaft 11 until the first speed is reached, whereupon motorconnections are reversed, the rotor is arrested by the pawl 17, and the stator drives the shaft 2 at the second speed.